You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

91 lines
2.4 KiB

// Copyright (c) 2016 The WebM project authors. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
#ifndef INCLUDE_WEBM_FILE_READER_H_
#define INCLUDE_WEBM_FILE_READER_H_
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <memory>
#include "./reader.h"
#include "./status.h"
/**
\file
A `Reader` implementation that reads from a `FILE*`.
*/
namespace webm {
/**
A `Reader` implementation that can read from `FILE*` resources.
*/
class FileReader : public Reader {
public:
/**
Constructs a new, empty reader.
*/
FileReader() = default;
/**
Constructs a new reader, using the provided file as the data source.
Ownership of the file is taken, and `std::fclose()` will be called when the
object is destroyed.
\param file The file to use as a data source. Must not be null. The file will
be closed (via `std::fclose()`) when the `FileReader`'s destructor runs.
*/
explicit FileReader(FILE* file);
/**
Constructs a new reader by moving the provided reader into the new reader.
\param other The source reader to move. After moving, it will be reset to an
empty stream.
*/
FileReader(FileReader&& other);
/**
Moves the provided reader into this reader.
\param other The source reader to move. After moving, it will be reset to an
empty stream. May be equal to `*this`, in which case this is a no-op.
\return `*this`.
*/
FileReader& operator=(FileReader&& other);
Status Read(std::size_t num_to_read, std::uint8_t* buffer,
std::uint64_t* num_actually_read) override;
Status Skip(std::uint64_t num_to_skip,
std::uint64_t* num_actually_skipped) override;
std::uint64_t Position() const override;
private:
struct FileCloseFunctor {
void operator()(FILE* file) const {
if (file)
std::fclose(file);
}
};
std::unique_ptr<FILE, FileCloseFunctor> file_;
// We can't rely on ftell() for the position (since it only returns long, and
// doesn't work on things like pipes); we need to manually track the reading
// position.
std::uint64_t position_ = 0;
};
} // namespace webm
#endif // INCLUDE_WEBM_FILE_READER_H_